Hello, First of all, you need to undergo one blood test for beta HCG to confirm pregnancy. It is more reliable than home pregnancy test. Other reasons of late period are hormonal imbalance, ovarian cyst, thyroid disturbance, over wt, irregular diet, pelvic or vaginal infection, stress etc. Following test report, you need to consult with gynecologist for other relevant investigation like USG scan, hormone assay etc. Take suggestive measures accordingly. Take healthy diet with iron supplement, avoid stress, maintain genital hygiene and take sound sleep. Good luck.